A nanotube array and a method for producing a nanotube array. The nanotube array has a substrate, a catalyst layer, which includes one or more subregions, on the surface of the substrate and at least one nanotube arranged on the surface of the catalyst layer, parallel to the surface of the substrate. The at least one nanotube being arranged parallel to the surface of the substrate results in a planar arrangement of at least one nanotube. Therefore, the nanotube array of the invention is suitable for coupling to conventional silicon microelectronics. Therefore, according to the invention it is possible for a nanotube array to be electronically coupled to macroscopic semiconductor electronics. Furthermore, the nanotube array according to the invention may have an electrically insulating layer between the substrate and the catalyst layer. This electrically insulating layer preferably has a topography which is such that the at least one nanotube rests on the electrically insulating layer at its end sections and is uncovered in its central section. As a result of the surface of the at least one nanotube being partly uncovered, the uncovered surface of the nanotube can be used as an active sensor surface. For example, the uncovered surface of the nanotube can come into operative contact with an atmosphere which surrounds the nanotube array. The electrical resistance of a nanotube changes significantly in the presence of certain gases. Thus because the nanotube is clear and uncovered, the nanotube array can be used in many sensor applications.